This invention retates to a structure and implement for positioning the light-receiving edge of a light conductor onto the focus of a lens.
It has often been the practice to focus solar ray by means of a lens, to guide solar rays into a light conductor and to transmit the solar ray through the light conductor to an optical desired position in order to use the solar ray for illumination or other purposes. One of such methods is to focus the solar ray by means of a Fresnel lens of about 40 cm diameter to guide the solar ray focussed by the lens into the light conductor having an edge surface of about 10 mm diameter arranged at the focus position of the lens, and to transmit the solar ray guided into the light conductor in such a manner through the light conductor to the optional desired position in order to use the solar ray for illumination or other purposes, for instance, as the light source for cultivating the plants in a room or an underground room, light source for nurturing the plants on the botton of the sea, or the light source for culturing chlorella, etc. However, according to such method, the focal distance of the lens turns out to be longer, for instance, about 40 cm, and therefore the device becomes large-scaled or voluminous. And further, the light collecting energy for each lens increases so that a highly heat-proof material needs to be used as the member placed near to the focus position of the lens, and the operator may probably be in danger of suffering from burning the operator's hands, etc. at the focus position when the operator performs the adjustment work for positioning the edge surface of the light conductor onto the focus position of the lens, and so on. According to the method, a large number of small lenses having a diameter of about 4 cm are used, and the edge surface of an optical fiber of 1 through 2 mm diameter is arranged at the focus position of each lens. The light collected by each lens is guided into the respective optical fibers, and the light delivered from the respective optical fibers is guided into an optical conductor having a large diameter, for instance a diameter of 10 through 30 mm and transmitted to the optional desired position through the light conductor.
According to this method mentioned above, the focal distance of the lens turns out to be small, for instance, about 4 cm. Therefore, it may be possible to realize the device manufactured in a small-scaled and thin style. On the contrary, since a large number of lenses are used, it may be troublesome to position the light-receiving edge surface of the optical fiber onto the focus of each lens and perform its maintenance operation.